Coupling for earth boring units



May 26, 1953 c. w. KANDLE COUPLING FOR EARTH bBORING UNITS ATTORNEYS.

INVENTR. Charles WKdncZZe Filed Jan. l6,V 1949 Patented May 26, 1953UNITED STATES PATENT OFFICE 2 Claims.

This invention relates to a coupling for anV learth boring unit. Theprincipal object of the invention is to provide a coupling for a boringunit which does-not 'interfere with the boring operation or removal fvention illustrated in the accompanying draW- ings.

In the drawings:

' Figure '1 is a side elevation of an earth boring unit coupled togethershown in a horizontal boring operation with parts broken away andsectioned, and illustrating a pipe and coupling to be assembled with theunit; l

Fig. 2 is an enlarged detail View illustrating the couplingof theinvention;. and

Fig. 3 is a section taken on line 3-3- of Fig. 1. In earth boringoperations it is often desirable to iirst drill a small hole whichserves as a guide hole in drilling a larger hole along the same course.One method of drilling a guide hole along a straight course is to employconnected lengths of pipe to the forward end of which is b attached alead screw. The pipe is rotated to rotate the screw and maintains thescrew in a straight course. Thus, for example, in making a horizontalhole beneath a sidewalk or pavement the course of the hole can be fairlyaccurately determined.

It also may be desirable to pull a guide pipe horizontally beneathpavement or sidewalks to eliminate the necessity of disturbing the pave--ment or walk and provide a hole through which 'pipe can be inserted asfor water or gas service.

In both of the operations described it may be desirable to coupletogether several lengths of pipe and it is the couple and couplingsystem employed to join a plurality of pipe lengths together forrotation to which the invention is directed.

The earth boring unit shown in the drawing comprises a plurality oflengths of pipe I laid end to end and within which is disposed aplurality of coupling members 2 for joining the pipe of each pair ofpipes 2 on the inside.

lengths together. The elongated tapered drill or screw 3 is threadedinto the one end of the coupled pipe lengths and the portable electricor air motor 4 is secured to the other endof the coupled pipe I torotate the unit in earth boring operations. Figure 1 illustrates theunit assembled and in horizontal position in boring a horizontal holebeneath a pavement. l

Each coupling member 2 is formed of a cylindrical bar of a diameter tofit within pipe I. The square head 5 is provided on one end of member2to fit within a complementary formed socket 6 of motor 4. Pin 'Iextends through socket 6 and head 5 to temporarily couple the motor toeach respective coupling member 2, as will be described. A couplingmember 2 extends within the ends Each member 2 is secured to one of thepipes I by a pair of pins 8 and to the next adjacent pipe by a secondpair of pins 8.

Pins 8 are spaced apart longitudinally and the pins of each pair extendthrough the coupling member 2 and pipe I at right angles to each other.Matching holes are provided in the pipes and coupling members forinsertion of pins 8 upon alignment of the holes.

Pins 8 are cylindrical and substantially of the same diameterthroughout` When the pins are inserted into place to join the couplingmembers and pipes together the outer portions of the pins li'e ush withthe circumferential surface of pipes I. In this position when the pipeis rotated the pins do not hit the sides of the hole being bored andconsequently do not interfere with rotation of the pipe.

Each pin 8 has a central groove 9. Groove 9 is engaged by ball IIJconfined within a hole in the coupling member 2 at right angles to thehole for pin 8 and aligned with groove 49 when pin 8 is positioned. BallI0 is backed by spring Il and set screw I2 which is threaded intocoupling 2. Each pin 8 when forced through its respective aligned holesin pipe I and coupling 2 engages ball I0 and forces the latter outwardlyagainst spring II until the ball is forced by the spring into engagementwith groove 9 to prevent lateral displacement of the pin. The ends ofpins 8 may be slightly tapered for engaging ball III to readily forcethe ball outwardly. Pin 8 is snapped out of the hole by merely pressingagainst one end of the pin to force ball I0 out of groove 9. Theconnement of the ball in the hole permits slight movement of the ballinwardly and outwardly and yet the ball is held in coupling 2 when pin 8is not in place. Pin 8 can be inserted through either side of pipe I andits respective coupling and the holes through the pipe and coupling toreceive a pin 8 are of the same diameter throughout.

In assembling an earth boring unit a coupling member 2 is rst secured bya pair of lpins 8 within a pipe I'. Head 5 and the outer portion of thecoupling member projects from one end of the pipe and lead screw 3 issecured to the other end of the pipe. Motor 4- is then coupled to head 5by slipping socket 8 over head 5 and inserting pin 1 therethrough. Motor4 is then started and pipe I and lead screw 3 rotated..

When lead drive 3 has worked its way into the ground motor 4 isuncoupled from head 5 and a second length of pipe I is slipped inabutting position next to the irst pipe I over the `outer portion of therst coupling member 2 and is secured to coupling 2 by insertion of avpair of' pins 8 at right angles to each other as described. The forwardportion of a second coupling member 2 is then secured within the secondlength `of .pipe I by a pair of pins 8. The motor I is then secured tothe head 5 of the second coupling member by pin 'I in order to rotatethe two pipes. and coupling members and drive lead screw 3 farther intothe ground. The disassembly of the motor and addition of pipe andcoupling and reassembly of the motor with the unit `ats described iscontinued until the hole desired 'is completed.

The motor can then be detached and the pipe .pulled out and uncoupledsuccessively until completely removed. The drilled hole then may serveas al guide for a lead screw in continued drilling operations if it isdesired to enlarge the hole, or a permanent pipe installation may be`made in the drilled hole. Pipe 'I keeps the screw 3 on a true course sothat the hole will come out where desired. Pins 8 and the detent andgroove arrangement provide vfor ready assembly of pipe and couplingmembers. Pins 8 being ilush with the pipe .when in position do. notinterfere with the pipe rotation or disturb the ground around the holeand are insertable from either side of the unit. Various embodiments ofthe invention may be employed Withinthe scope of the accompanyingclaims.`

I claim:

1. In a coupling system for an'earth boring unit having a drill securedto a plurality of lengths of pipe laid end to end and a motor to rotatethe same, a coupling comprising a generally cylindrical member with theone end portion disposed in one length of pipe and the other end portionthereof disposed in another length of pipe, a head on said one endportion of said coupling member to be engaged by said motor, cylindricalpins extending transversely through each pipe and coupling to Join thesame together for rotation with'the outer ends of the pins flush withthe circumferential surface of the pipe to prevent engagement with theground being bored. and means to secure said pins against displacement.1

2. InaA coupling system for an earth boring unit having a drill securedto a plurality o! lengths 'of pipe laid end to end and a motor to rotatethe same, a coupling comprising a gen'.

erally cylindrical member with one end portion 4disposed in one lengthof pipe and the other end portion thereof disposed in another length ofpipe.. a head on said one end portion of Said coupling member engaged bysaid motor, cylindrical pins extending transversely through each pipeand coupling to join the same together for rotation, with the outer endsof the pins flush with the circumferential surface of the pipe toprevent engagement with theground. being bored, a centralcircumferential groove in. each. pin. and a spring pressed ball detentdisposed in said groove when a pin is in place to prevent lateraldisplacement of the same relative to said. pipe.

CHARLES W. KANDLE.

